JP2022022783A - Fuel cell joint mold - Google Patents

Abstract

To provide a fuel cell joint mold that can avoid damage to a separator and obtain a fuel cell with good performance by reducing a problem of in-plane pressure bias of the separator due to dimensional variation in the stacking direction that occurs in the separator after cell formation.SOLUTION: A fuel cell joint mold 1 includes a first mold 10 and a second mold 20, and the second mold 20 includes an outer element 23 that presses and heats a joint portion 53, and an inlet 21 that presses and heats a gas flow path 51, and the plan view shape of the surface of the inlet 21 that abuts on the gas flow path 51 is the same as the plan view shape of the gas flow path 51.SELECTED DRAWING: Figure 6

Description

The present invention relates to a joining mold for a fuel cell.

The fuel cell of a fuel cell is configured by joining an electrode assembly and each of a pair of separators. In order to perform such joining, a technique for joining a fuel cell by using a die for a heating press has been disclosed.

For example, Patent Document 1 discloses a joining die for joining a gasket-separator member joint body, which has a nesting die that heat-presses the separator and forms a gasket on the separator. .. After forming the gasket, the nesting die presses and heats the gas flow path of the separator and the portions formed around the gas flow path together. That is, the nesting die disclosed in Patent Document 1 heat-presses the entire main surface of the separator.

Japanese Unexamined Patent Publication No. 2017-168230

By the way, the joining of the fuel cell, that is, the joining of the pair of separators and the electrode assembly is realized by welding the thermoplastic resin layer portion of the resin frame of the electrode assembly melted by heating and each separator. Further, in general, the separator is formed around the gas flow path having the largest dimension in the stacking direction in the thickness direction, that is, the stacking direction at the time of stacking, and is formed around the gas flow path. Also has a peripheral portion with small dimensions in the stacking direction. When such a separator is joined using a mold such as the nesting mold disclosed in Patent Document 1, both the gas flow path and the peripheral portion are pressed and heated by the mold. In this way, not only the portion of the thermoplastic resin layer of the resin frame corresponding to the gas flow path but also the portion of the thermoplastic resin layer of the resin frame corresponding to the peripheral portion is melted by the heat from the mold. Therefore, the gas flow path and the peripheral portion are pressed against the core layer of the resin frame and come into contact with the core layer. For this reason, in the fuel cell after joining (after cell formation), the separator has a variation in dimensions in the stacking direction. When such variations occur, the problem of uneven pressure in the plane of the separator may occur. As a result, the separator may be damaged due to the deviation of the in-plane pressure, which may greatly affect the performance of the fuel cell.

The present invention has been invented in view of such circumstances, and an object of the present invention is to reduce the problem of deviation of the in-plane pressure of the separator due to dimensional variation in the stacking direction that occurs in the separator after cell formation. It is an object of the present invention to provide a bonding mold for a fuel cell, which can avoid damage to the separator and obtain a fuel cell having good performance.

The fuel cell cell bonding die according to one aspect of the present invention is laminated on both main surfaces of the electrode assembly and the resin frame of the electrode assembly, and each is provided around the gas flow path and the gas flow path. A fuel cell in which a laminate composed of a first separator and a second separator having a peripheral portion and a joint portion provided on the peripheral edge side of the peripheral portion is bonded by heat pressing in the stacking direction. A bonding mold for a fuel cell to form a cell, which is arranged on a side facing the first mold and a first mold on which the laminate is placed in a state of being in contact with the first separator. The second mold comprises a second mold that presses the second separator of the laminated body by moving relative to the first mold in the stacking direction, and the second mold presses and heats the joint portion. It has an outer element and an alloy that presses and heats the gas flow path, and the plan view shape of the surface that abuts on the gas flow path of the nest is the same as the plan view shape of the gas flow path.

In the fuel cell joining die of the above aspect, when the heating press is performed, the insert of the second die presses the gas flow path, but does not press the peripheral portion around the gas flow path. Therefore, during the heating press (during cell formation), the insert of the second die enters heat only into the gas flow path and does not enter heat into the peripheral portion. In this way, the portion of the resin frame that comes into contact with the gas flow path of the second separator is melted by heat from the insert of the second mold, and a part of the resin frame flows into the gas flow path. As a result, the dimension of the gas flow path in the stacking direction is smaller than that before the heating press. On the other hand, the peripheral portion is not heated by the insert of the second mold. Therefore, the portion of the resin frame corresponding to the peripheral portion of the second separator does not melt. Therefore, after the heating press (after cell formation), the dimensions of the peripheral portion in the stacking direction do not change. As described above, in the second separator after cell formation, the dimension of the gas flow path in the stacking direction and the dimension of the peripheral portion in the stacking direction are substantially the same. Therefore, there is almost no variation in the dimensions of the second separator after cell formation in the stacking direction. Therefore, there is no problem of deviation of the in-plane pressure of the second separator due to the variation in the dimensions of the second separator in the stacking direction. As a result, it is possible to avoid damage to the second separator due to the deviation of the in-plane pressure of the second separator. The same applies to the first separator. In this way, it is possible to avoid the problem of breakage of the separator related to each of the first separator after cell formation and the second separator after cell formation. A fuel cell having good performance can be configured by such a first separator after cell formation and a second separator after cell formation.

According to the present invention, by reducing the problem of uneven pressure in the plane of the separator due to dimensional variation in the stacking direction that occurs in the separator after cell formation, damage to the separator can be avoided and a fuel cell having good performance can be obtained. It becomes possible to provide a joint mold for a fuel cell that can be obtained.

It is a perspective view which shows the outline of each structure of the fuel cell of the fuel cell which concerns on this embodiment, and the fuel cell before being joined. It is sectional drawing of the line AA of FIG. It is a top view of the laminated body which concerns on this embodiment. It is a cross-sectional view of BB of FIG. It is a figure which shows the structure of the nesting of the 2nd mold which concerns on this embodiment. It is an overall view which shows the heating press state to the laminated body by the bonding die which concerns on this embodiment. It is a partially enlarged view which shows the heating press state to the laminated body by the bonding die which concerns on this embodiment. It is a partially enlarged view which shows the heating press state to the laminated body by the bonding die which concerns on a comparative example.

An embodiment of the present invention will be described below. In the description of the following drawings, the same or similar components are represented by the same or similar reference numerals. The drawings are examples, and the dimensions and shapes of each part are schematic, and the technical scope of the present invention should not be limited to the embodiment.

[The present embodiment]
<Outline of joining with joining mold 1>
First, the outline of joining by the joining mold 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing an outline of each configuration of a fuel cell cell joining mold 1 and a fuel cell before joining according to the present embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG.

The joining die 1 according to the present embodiment is an example of a heating press die for joining a fuel cell. Specifically, the joining die 1 is subjected to heat pressing from both sides of the laminated body 3 in the laminating direction of the fuel cell, that is, the laminated body 3 before being joined, so that each of the laminated bodies 3 is formed. It is a mold for joining the configurations to each other.

As shown in FIG. 1, the joining die 1 includes a first die 10 and a second die 20 arranged so as to face each other. Further, as shown in FIG. 2, the laminated body 3 to be joined by the joining mold 1 has an electrode assembly 30 and a first separator 40 and a second separator 50 laminated on both main surfaces of the electrode assembly 30. Have.

In this way, when the heating press is performed, the bonding die 1 is subjected to the heating press in the second direction in the stacking direction that the first die 10 gives to the first separator 40, and the second die 20 gives to the second separator 50. Using a heating press in the first direction in the stacking direction, the electrode assembly 30 and each of the first separator 40 and the second separator 50 are joined to form a fuel cell.

Hereinafter, the characteristics of the laminated body 3 to be joined will be described, and then the details of the joining mold 1 will be described. The state in which the first separator 40, the electrode assembly 30, and the second separator 50 are laminated to form the laminated body 3 may be referred to as a “laminated state”, and a state in which the laminated bodies 3 are joined to form a fuel cell is defined as a state in which the laminated body 3 is formed. Sometimes referred to as "celled state". Further, a state in which a plurality of fuel cell cells are stacked and then stacked by an end plate to form a fuel cell may be referred to as a "stacked state". Also, a heating press

<Details of laminated body 3>
Next, with reference to FIGS. 1 to 4, the details of the laminated body 3 according to the present embodiment, that is, the configurations of the electrode assembly 30, the first separator 40, and the second separator 50 will be described. FIG. 3 is a plan view of the laminated body 3 according to the present embodiment. FIG. 4 is a cross-sectional view taken along the line BB of FIG. Note that FIG. 4 omits the display of configurations other than the resin frame 32 of the electrode assembly 30.

(Electrode assembly 30)
The electrode assembly 30 is a sheet-like member, and has a rectangular shape in a plan view. Further, the electrode assembly 30 has a membrane electrode assembly (MEA) 31 and a resin frame 32 bonded to one side surface 312 of the MEA 31 by an adhesive material of a thermosetting resin.

The MEA 31 constitutes a power generation portion of a fuel cell. Further, the MEA 31 has an electrolyte membrane 311, a first electrode 314 bonded to the main surface on one side of the electrolyte membrane 311 and a second electrode 315 bonded to the main surface on the other side of the electrolyte membrane 311.

The electrolyte membrane 311 is, for example, a perfluorosulfonic acid ion exchange membrane using an ionomer resin. The first electrode 314 is an anode electrode (or cathode electrode), and the second electrode 315 is a cathode electrode (or cathode electrode). Further, both the first electrode 314 and the second electrode 315 have a metal catalyst layer provided so as to be in contact with the electrolyte membrane 311 and a diffusion layer made of a porous body member provided on the catalyst layer. Has.

The resin frame 32 is a sheet-like member, and the plan view shape is a frame shape. When adhered to the surface 312 of the MEA 31, the resin frame 32 is located on the outer peripheral side of the MEA 31. In the laminated state, the resin frame 32 is provided so as to surround the second electrode 315. Further, the resin frame 32 has a plurality of flow path holes provided on both sides of the central opening, which form the gas flow path and the refrigerant flow path of the fuel cell. Each of these flow path holes corresponds to each of the plurality of flow holes of the second separator 50, which will be described later, and has the same shape and function. Therefore, the detailed description of the flow path hole of the resin frame 32 will be omitted.

Further, as shown in FIG. 4, the resin frame 32 has a core layer 321 and two thermoplastic resin layers 322 provided on both main surfaces of the core layer 321. When heated, the thermoplastic resin layer 322 is a portion that is melted by the heat received, while the core layer 321 is a portion that is not melted by the heat received. In this way, the resin frame 32 realizes thermal bonding between the electrode assembly 30 and each of the first separator 40 and the second separator 50 via the thermoplastic resin layer 322. Further, in the resin frame 32, the positions of the first separator 40 and the second separator 50 in the stacking direction with respect to the electrode assembly 30 are restricted via the core layer 321.

(First Separator 40 and Second Separator 50)
Next, the details of the first separator 40 and the second separator 50 will be described with reference to FIGS. 1 to 4.

The first separator 40 and the second separator 50 have a function of collecting electric power generated by the MEA 31 and a function of partitioning each MEA 31 of a plurality of stacked fuel cell cells in a stacked state. It is a separator. Further, the first separator 40 and the second separator 50 are between a gas flow path inside each fuel cell for flowing a reaction gas to MEA 31 and an outside of the fuel cell, that is, between adjacent fuel cell cells. It constitutes a fuel cell flow path for flowing a fuel in.

Further, in the present embodiment, the first separator 40 has the same configuration as the second separator 50, as shown in FIG. Therefore, in the following description, the configuration of the second separator 50 will be mainly described, and the description of the configuration of the first separator 40 will be omitted.

The second separator 50 is a thin plate-shaped member, and has a rectangular shape whose plan view shape has the same dimensions as the plan view shape of the electrode assembly 30. The material of the second separator 50 is, for example, a metal such as titanium, a titanium alloy, or stainless steel.

Further, as shown in FIG. 3, the second separator 50 includes a gas flow path 51 provided in an intermediate portion in the main surface direction of the second separator 50 and a peripheral portion 52 provided around the gas flow path 51. It has a joint portion 53 provided on the peripheral edge side of the second separator 50 with respect to the peripheral portion 52. Further, the second separator 50 has a plurality of flow path holes provided in the joint portion 53 and a gasket 54 provided in the joint portion 53. The first separator 40 also has a gas flow path 41, a peripheral portion 42, a joint portion 43, and a flow path hole corresponding to each configuration of the second separator 50.

The gas flow path 51 is a gas flow path on the diffusion layer side of the second electrode 315 for supplying the fuel gas (or oxidant gas) to the MEA 31. Further, the gas flow path 41 of the first separator 40 corresponding to the gas flow path 51 is a gas flow path on the diffusion layer side of the first electrode 314 for supplying the oxidant gas (or fuel gas) to the MEA 31. .. As shown in FIG. 4, the gas flow path 51 has a comb shape. Further, as shown in FIG. 3, the gas flow path 51 has a first gas flow path 511 and two second gas flow paths 512 formed on both sides of the first gas flow path 511. The two second gas flow paths 512 have the first gas flow path 511 as an inflow path and an inflow / outflow path of a pair of oxidant gas flow paths (or a pair of fuel gas flow paths) in the flow path holes of the second separator 50. It is connected to each of the holes constituting the passage.

In the laminated state, as shown in FIGS. 3 and 4, the first gas flow path 511 of the gas flow paths 51 is located on the diffusion layer of the second electrode 315 of the electrode assembly 30, and the second gas flow path is located. The path 512 is located on the thermoplastic resin layer 322 of the resin frame 32 of the electrode assembly 30. The gas flow path 51 is a portion of the electrode assembly 30 that projects in a direction away from the resin frame 32, that is, in a second direction in the stacking direction. Further, the gas flow path 51 protrudes from the electrode assembly 30 in the second direction in the stacking direction from the peripheral portion 52 and the joint portion 53. In the following, the surface of the gas flow path 51 on the tip side in the protrusion direction is referred to as "tip surface 510", and the surface of the gas flow path 51 on the root side in the protrusion direction, that is, the surface in contact with the second separator 50 and the resin frame 32. May be referred to as "contact surface 561".

In the laminated state (before cell formation), the contact surface 561 of the gas flow path 51 is in contact with the thermoplastic resin layer 322 of the resin frame 32. In the stacking direction, the distance from the tip surface 510 of the gas flow path 51 to the contact surface 501 is H1. The distance from the tip surface 510 of the gas flow path 51 to the core layer 321 of the resin frame 32 is H3. Hereinafter, the distance from the tip surface 510 of the gas flow path 51 to the core layer 321 of the resin frame 32 in the stacking direction may be referred to as “dimensions in the stacking direction” of the gas flow path 51. Therefore, the dimension of the gas flow path 51 in the stacking direction is H3. Further, the dimension H1 is the height of the flow path of the gas flow path 51. The same applies to the peripheral portion 52 described later.

As shown in FIG. 4, the peripheral portion 52 has a comb shape. As shown in FIG. 3, the peripheral portion 52 is formed so as to surround the gas flow path 51. In the laminated state, the peripheral portion 52 protrudes from the electrode assembly 30 in the second direction in the stacking direction from the joint portion 53. In the following, the surface of the peripheral portion 52 on the tip side in the protrusion direction is referred to as "tip surface 520", and the surface of the peripheral portion 52 on the root side in the protrusion direction, that is, the surface in contact with the second separator 50 and the resin frame 32 is referred to as "the surface". It may be called "contact surface 562".

In the laminated state (before cell formation), the contact surface 562 of the peripheral portion 52 is in contact with the thermoplastic resin layer 322 of the resin frame 32. In the stacking direction, the distance from the tip surface 520 of the peripheral portion 52 to the contact surface 562 is H2. The distance from the tip surface 520 of the peripheral portion 52 to the core layer 321 of the resin frame 32, that is, the dimension of the peripheral portion 52 in the stacking direction is H4.

Here, the distance H2 from the tip surface 520 of the peripheral portion 52 to the contact surface 562 is smaller than the distance H1 from the tip surface 510 of the gas flow path 51 to the contact surface 501. The dimension H4 in the stacking direction of the peripheral portion 52 is smaller than the dimension H3 in the stacking direction of the gas flow path 51. Further, the dimension H1 is substantially the same as the dimension H4.

The joint portion 53 is a portion that comes into contact with the resin frame 32 of the electrode assembly 30 in the laminated state. At the time of hot pressing, the joint portion 53 is a portion that receives the hot press by the second die 20. In this case, the pressure given to the joint portion 53 by the second die for performing the heating press is larger than the pressure given to the gas flow path 51 by the second die. After the heat press is performed in this way, the joint portion 53 is welded to the resin frame 32 via the thermoplastic resin layer 322 of the resin frame 32 melted by heat. In this way, the second separator 50 is joined to the main surface on one side of the electrode assembly 30. Further, in this case, the gas flow path 51 is in contact with the core layer 321 of the resin frame 32.

The plurality of flow path holes of the second separator 50 form a hole portion 531 and a hole portion 532 that form a fuel gas flow path (or an oxidant gas flow path), and an oxidant gas flow path (or a fuel gas flow path). It has a hole portion 541 and a hole portion 542 to be formed, and a hole portion 551 and a hole portion 552 constituting the refrigerant flow path. Further, the hole 531 and the hole 541 and the hole 551 are holes constituting the inflow passage, and the hole 532, the hole 542 and the hole 552 are holes constituting the outflow passage.

As shown in FIG. 3, each of the hole portion 541 and the hole portion 542 is connected to the first gas flow path 511 by the second gas flow path 512. In this way, in the stack state, in the gas flow path on the second separator 50 side, the gas flowing in from the hole 541 of the inflow passage is the one second gas flow path 512, the first gas flow path 511, and the other second gas. It can flow into the hole 542 of the outflow passage through the flow path 512. The gas flow path on the second separator 50 side is partitioned by a seal member or the like (not shown) provided between the second separator 50 and the electrode assembly 30. The same applies to the gas flow path on the first separator 40 side.

The gasket 54 is an example of a sealing member. As shown in FIG. 3, the gasket 54 is provided in the joint portion 53 so as to surround the gas flow path 51 and the holes 551 and 552 constituting the refrigerant flow path. In the stacked state, the gasket 54 is deformed by pressing the adjacent fuel cell cells and seals the space between the adjacent fuel cell cells. In this way, the refrigerant can flow into the refrigerant flow path between the adjacent fuel cell cells sealed by the gasket 54.

Next, with reference to FIGS. 1 to 6, the details of the pair of dies in the joining die 1 according to the present embodiment, that is, the first die 10 and the second die 20 will be described. FIG. 5 is a diagram showing a configuration of a nest 21 of the second mold 20 according to the present embodiment. FIG. 6 is an overall view showing a heat-pressed state of the laminated body 3 by the joining mold 1 according to the present embodiment.

The first mold 10 is a mold on which the laminated body 3 is placed. As shown in FIG. 1, the first mold 10 has an inner element 11 formed in the central portion of the main surface of the first mold 10 and an outer element 13 formed around the inner element 11. As shown in FIG. 2, the height of the outer element 13 is larger than the height of the inner element 11 in the stacking direction.

The inner child 11 has a block shape. In the joining die 1, the inner element 11 is provided at a position corresponding to the element 21 of the second die 20 described later. Further, the inner element 11 has the same shape as the element 21 of the second mold 20. Therefore, the details of the inner element 11 will be described together with the configuration of the element 21 of the second mold 20. As shown in FIG. 1, the plan view shape of the upper surface of the inner core 11 is the same as the plan view shape of the gas flow path 41 of the first separator 40.

The outer child 13 has a frame shape. In the joining die 1, the outer element 13 is provided at a position corresponding to the outer element 23 of the second mold 20, which will be described later. Further, the outer element 13 has the same shape as the outer element 23 of the second mold 20.

When the laminated body 3 is placed, as shown in FIG. 6, the inner element 11 abuts on the gas flow path 41 of the first separator 40, and the outer element 13 abuts on the joint portion 43 of the first separator 40. Can be done. In this way, the laminated body 3 is supported by the inner element 11 and the outer element 13 of the first mold 10.

Further, the outer element 13 and the inner element 11 have a function of serving as a pressing portion at the time of hot pressing. At the time of hot pressing (during cell formation), each of the outer element 13 and the inner element 11 presses the laminated body 3 toward the second direction in the laminating direction by the reaction force of the forces from the outer element 23 and the inner element 21.

Further, a heating unit (not shown) for heating the inner child 11 and the outer child 13 is built in the first mold 10 on the first direction side of the inner child 11 and the outer child 13. In this way, during the heating press (during cell formation), the inner element 11 and the outer element 13 press the gas flow path 41 and the joint portion 43 of the laminated body 3 toward the second direction in the stacking direction, and the gas flow path 41 and the outer element 13 are pressed. The heat from the heating portion can be transferred to a part of the thermoplastic resin layer 322 of the joint portion 43, the gas flow path 41, and the resin frame 32 in contact with the joint portion 43.

(2nd mold 20)
The second mold 20 is arranged on the side facing the first mold 10, and by moving relative to the first mold 10 in the stacking direction, the laminated body 3 is heated together with the first mold 10. It is a die for pressing. Before the heating press starts, the second die 20 is separated from the first die 10.

Further, as shown in FIG. 6, in the second mold 20, the insert 21 provided in the central portion of the main surface of the second mold 20 and the outer element 23 formed around the insert 21 are provided. Have. The insert 21 is attached to the main surface of the second mold 20 by a spring member 22. In other words, the insert 21 is suspended from the main surface of the second mold 20 by the spring member 22. Thus, as shown in FIG. 2, before the start of the heating press, the insert 21 is located on the first direction side in the stacking direction with respect to the outer element 23 in the stacking direction.

Further, as shown in FIG. 5, the nest 21 is a plate-shaped member. In the joining die 1, the insert 21 is provided at a position corresponding to the inner element 11 of the first die 10. Further, the nesting 21 is a position corresponding to a pressing portion 210 that presses the gas flow path 51 of the second separator 50 and a part around the pressing portion 210, that is, a peripheral portion 52 of the second separator 50 at the time of cell formation. It has two niger portions 213 formed in. In other words, the pressing portion 210 is a protruding portion of the nest 21. The two nigga portions 213 correspond to the cutout portion of the nest 21.

Further, as shown in FIG. 5, the plan view shape of the surface of the pressing portion 210 of the insert 21 that abuts on the gas flow path 51 is the same as the plan view shape of the gas flow path 51. Specifically, the pressing portion 210 has a first pressing portion 211 that presses the first gas flow path 511 and two second gas flow paths 512 formed on both sides of the first pressing portion 211 at the time of cell formation. It has two second pressing portions 212 for pressing each of the above. The first pressing portion 211 and the two second pressing portions 212 are integrally formed. In this way, at the time of cell formation, the pressing portion 210 can press the gas flow path 51 toward the first direction in the stacking direction.

The two niger portions 213 are portions corresponding to the peripheral portion 52 of the second separator 50. On the other hand, at the time of cell formation, the two niger portions 213 do not abut on the peripheral portion 52 and are separated from the tip surface 520 of the peripheral portion 52. In other words, at the time of cell formation, the peripheral portion 52 is not pressed by the nest 21 by the two niger portions 213.

The outer element 23 has the same shape as the outer element 13 of the first separator 40, and has a frame shape in a plan view. In the joining die 1, the outer element 23 is provided at a position corresponding to the outer element 13 of the first die 10. At the time of hot pressing (at the time of cell formation), the outer element 23 is a portion that comes into contact with the joint portion 53 of the second separator 50 of the laminated body 3. In this way, at the time of hot pressing, the outer element 23 can press the joint portion 53 toward the first direction in the stacking direction.

Further, as described above, the insert 21 is suspended from the main surface of the second mold 20 by the spring member 22. Therefore, at the time of cell formation, after the insert 21 of the second mold 20 comes into contact with the gas flow path 51 of the second separator 50 and stops moving, the outer element 23 moves toward the first direction in the stacking direction. It moves and comes into contact with the joint portion 53 of the second separator 50. Therefore, the pressing force applied by the insert 21 to the gas flow path 51 is smaller than the pressing force applied by the outer element 23 to the joint portion 53. As a result, the diffusion layer of the second electrode 315 located in the first direction in the stacking direction with respect to the first gas flow path 511 of the gas flow path 51 receives excessive pressing force from the second mold 20 and seats. You can avoid giving in.

Further, a heating portion (not shown) for heating the inlet 21 and the outer element 23 is built in the second mold 20 on the second direction side of the inlet 21 and the outer element 23. In this way, during the heating press, the inlet 21 and the outer element 23 press the gas flow path 51 and the joint portion 53 of the laminated body 3 toward the second direction in the stacking direction, and are in contact with the joint portion 43 and the joint portion 43. The heat from the heating portion can be transferred to the thermoplastic resin layer 322 of the resin frame 32 in contact with the resin frame 32. Further, in this case, the two niger portions 213 of the nest 21 do not come into contact with the peripheral portion 52. Therefore, the peripheral portion 52 is not heated by the two nigetous portions 213 of the insert 21.

<Joining process by joining mold 1>
Subsequently, the joining process by the joining mold 1 will be described with reference to FIGS. 6 and 7.

First, the laminated body 3 is placed on the first mold 10.

Here, the first separator 40, the electrode assembly 30, and the second separator 50 may be laminated to form a laminated body 3, and then the laminated body 3 may be placed on the first mold 10. Further, the first separator 40, the electrode assembly 30, and the second separator 50 may be laminated one by one while being placed on the first mold 10. Further, when mounting, the gas flow path 41 of the first separator 40 is placed on the upper surface of the inner core 11, and the joint portion 43 of the first separator 40 is placed on the upper surface of the outer core 13.

Subsequently, the second die moves toward the first direction in the laminating direction, and the laminated body 3 is heat-pressed together with the first die 10.

Specifically, the inlet 21 and the outer element 23 of the second mold 20 press the gas flow path 51 and the joint portion 53 of the second separator 50 of the laminated body 3 toward the first direction, and the gas flow. Heat is input to the thermoplastic resin layer 322 on the second direction side of the resin frame 32 via the path 51 and the joint portion 53. At the same time, the inner element 11 and the outer element 13 of the first mold 10 use the reaction force against the pressing force of the inlet 21 and the outer element 23 of the second mold 20, respectively, and the first separator 40 of the laminated body 3 is used. The gas flow path 41 and the joint portion 43 of the above are pressed toward the second direction, and heat is input to the thermoplastic resin layer 322 on the first direction side of the resin frame 32 via the gas flow path 41 and the joint portion 43. ..

In this way, on the second separator 50 side, the portion of the thermoplastic resin layer 322 on the second direction side of the resin frame 32 that comes into contact with the gas flow path 51 and the joint portion 53 of the second separator 50 is melted by heating and gas. The flow path 51 and the joint portion 53 are welded to the resin frame 32. As a result, the second separator 50 is joined to the electrode assembly 30 via welding of each of the gas flow path 51 and the joining portion 53 with the resin frame 32 of the electrode assembly 30.

Further, on the first separator 40 side, the portion of the thermoplastic resin layer 322 on the first direction side of the resin frame 32 that comes into contact with the gas flow path 41 and the joint portion 43 of the first separator 40 is melted by heating and gas. The flow path 41 and the joint portion 43 are welded to the resin frame 32. As a result, the first separator 40 is joined to the electrode assembly 30 via welding of each of the gas flow path 41 and the joining portion 43 with the resin frame 32 of the electrode assembly 30.

After the first separator 40 and the second separator 50 are completely joined to both peripheral surfaces of the electrode assembly 30, the joining by the joining mold 1 is completed.

<Joining effect by joining mold 1>
Subsequently, with reference to FIGS. 7 and 8, the joining effect by the joining die 1 according to the present embodiment will be described while comparing with the joining effect by the joining die according to the comparative example. FIG. 7 is a partially enlarged view showing a state of being heated and pressed onto the laminated body 3 by the joining mold 1 according to the present embodiment. FIG. 8 is a partially enlarged view showing a state of heat pressing on the laminated body 3 by the joining mold according to the comparative example.

Here, first, the configuration of the joining mold according to the comparative example will be briefly described. The difference between the joining mold according to the comparative example and the joining mold 1 according to the present embodiment is that the alloy 200 of the second mold of the joining mold according to the comparative example is the second mold according to the present embodiment. It does not have the niger portion 213 of the alloy 21 of 20. That is, the nesting 200 according to the comparative example is a plate-shaped member having no cutout portion formed therein, and the nesting 200 according to the comparative example has a rectangular shape in a plan view.

(The present embodiment)
In the joining die 1 according to the present embodiment, the insert 21 of the second mold 20 presses the gas flow path 51 at the time of cell formation, but does not press the peripheral portion 52 around the gas flow path 51. Further, as shown in FIG. 7, at the time of cell formation, the nesting 21 of the second mold 20 is separated from the peripheral portion 52 via the niger portion 213 by using a certain distance. Therefore, at the time of cell formation, the insert 21 of the second mold 20 enters heat only into the gas flow path 51, and does not enter heat into the peripheral portion 52.

In this way, as shown in FIG. 7, the portion of the thermoplastic resin layer 322 on the second direction side of the resin frame 32 that comes into contact with the gas flow path 51 of the second separator 50 is the nest 21 of the second mold 20. It is melted by heat from the pressing portion 210 of the above, and a part of it flows into the flow path of the gas flow path 51. Further, at this time, the gas flow path 51 is pressed in the first direction in the stacking direction by the pressing portion 210 of the insert 21 of the second mold 20. The contact surface 561 of the gas flow path 51 comes into contact with the core layer 321 of the resin frame 32. As a result, the dimension of the gas flow path 51 in the stacking direction is smaller than that before the cell formation. Specifically, the dimension of the gas flow path 51 in the stacking direction is reduced from H3 before cell formation to H1.

On the other hand, the peripheral portion 52 is not heated by the insert 21 of the second mold 20. Therefore, the portion of the thermoplastic resin layer 322 on the second direction side of the resin frame 32 corresponding to the peripheral portion 52 of the second separator 50 does not melt. Therefore, after the cell formation, the contact surface 562 of the peripheral portion 52 is in contact with the thermoplastic resin layer 322 of the resin frame 32 as before the cell formation. Therefore, the dimensions of the peripheral portion 52 in the stacking direction do not change as compared with those before the cell formation. That is, after cell formation, the dimension of the peripheral portion 52 in the stacking direction remains H4.

As described above, in the second separator 50 after cell formation, the dimension of the gas flow path 51 in the stacking direction is H1, and the dimension of the peripheral portion 52 in the stacking direction is H4. Further, as described above, the dimension H1 is substantially the same as the dimension H4. Therefore, there is almost no variation in the dimensions of the second separator 50 in the stacking direction after cell formation. Therefore, there is no problem of deviation of the in-plane pressure of the second separator 50 due to the variation in the dimensions of the second separator 50 in the stacking direction. As a result, it is possible to avoid damage to the second separator 50 due to the deviation of the in-plane pressure of the second separator 50.

Further, the state of the first separator 40 after cell formation is the same as the state of the second separator 50 after cell formation described above. Therefore, detailed description of the first separator 40 after cell formation will be omitted. Similar to the second separator 50 after cell formation, there is almost no variation in the dimensions of the first separator 40 after cell formation in the stacking direction. Therefore, there is no problem of deviation of the in-plane pressure of the first separator 40 due to the variation in the dimensions of the first separator 40 in the stacking direction. As a result, it is possible to avoid damage to the second separator 50 due to the deviation of the in-plane pressure of the first separator 40.

In this way, it is possible to avoid the problem of damage to the separators of the first separator 40 after cell formation and the second separator 50 after cell formation. The fuel cell having good performance can be configured by the first separator 40 after cell formation and the second separator 50 after cell formation.

(Comparative example)
On the other hand, as shown in FIG. 8, at the time of cell formation, the insert 200 of the second mold according to the comparative example does not abut on the peripheral portion 52 of the second separator 50, but with respect to the peripheral portion 52. It is located very close. Therefore, the nest 200 according to the comparative example heats up to the peripheral portion 52.

In this way, as shown in FIG. 8, the portion of the thermoplastic resin layer 322 on the second direction side of the resin frame 32 that comes into contact with the gas flow path 51 and the peripheral portion 52 of the second separator 50 is included in the comparative example. It is melted by heat from the child 200, and a part of it flows into the flow path of the gas flow path 51 and the comb-shaped groove of the peripheral portion 52. Further, at this time, the gas flow path 51 and the peripheral portion 52 are pressed in the first direction in the stacking direction by the pressing portion 210 of the insert 200 of the second mold according to the comparative example. The contact surface 561 of the gas flow path 51 and the contact surface 562 of the peripheral portion 52 are in contact with the core layer 321 of the resin frame 32. As a result, both the dimension of the gas flow path 51 in the stacking direction and the dimension of the peripheral portion 52 in the stacking direction are smaller than those before the cell formation. Specifically, the dimension of the gas flow path 51 in the stacking direction is reduced from H3 before cell formation to H1. The dimension of the peripheral portion 52 in the stacking direction is reduced from H4 before cell formation to H2.

As described above, in the second separator 50 after cell formation according to the comparative example, the dimension of the gas flow path 51 in the stacking direction is H1, and the dimension of the peripheral portion 52 in the stacking direction is H2. Further, as described above, the dimension H2 is smaller than the dimension H1. For this reason, the dimensions of the second separator 50 after cell formation according to the comparative example vary in the stacking direction. Therefore, the problem of uneven pressure in the in-plane pressure of the second separator 50 occurs. As a result, the second separator 50 may be damaged due to the bias of the in-plane pressure of the second separator 50.

Further, the first separator 40 after cell formation according to the comparative example may be damaged in the same manner as the state of the second separator 50 after cell formation according to the comparative example described above.

As described above, there is a possibility that the separator damage problem related to each of the cellized first separator 40 and the cellified second separator 50 according to the comparative example may occur. The damaged first separator 40 after cell formation and the second separator 50 after cell formation have a great influence on the fuel cell cell performance.

As described above, the joining mold 1 according to the present embodiment employs the nesting 21 that presses and heats only the gas flow path, and the surface of the separator due to the dimensional variation in the stacking direction that occurs in the separator after cell formation. By reducing the problem of uneven internal pressure, it is possible to avoid damage to the separator and obtain a fuel cell with good performance.

The embodiments described above are for facilitating the understanding of the present invention, and are not for limiting the interpretation of the present invention. Each element included in the embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those exemplified, and can be appropriately changed. Further, it is possible to partially replace or combine the configurations shown in different embodiments.

1 ... Joining die, 3 ... Laminated body, 10 ... First mold, 13, 23 ... Outer element, 20 ... Second mold, 21 ... Insertion, 30 ... Electrode assembly, 40 ... First separator, 41, 51 ... gas flow path, 42, 52 ... peripheral portion, 43, 53 ... joint portion, 50 ... second separator

Claims (1)

The electrode assembly and the resin frame of the electrode assembly are laminated so as to be in contact with each other, each of which is a gas flow path, a peripheral portion provided around the gas flow path, and a peripheral side of the peripheral portion. The laminated body composed of the first separator and the second separator having the joint portion provided in the above is joined by heat pressing in the stacking direction to form a fuel cell. It is an alloy type
With the first mold on which the laminated body is placed in a state of being in contact with the first separator,
A second mold, which is arranged on the side facing the first mold and presses the second separator of the laminated body by moving relative to the first mold in the stacking direction.
Equipped with
The second mold has an outer element that presses and heats the joint portion, and an element that presses and heats the gas flow path.
The plan view shape of the surface of the nest that comes into contact with the gas flow path is the same as the plan view shape of the gas flow path.
Fuel cell cell joint mold.

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